Spatial and Temporal Characteristics of Concurrent Droughts and Floods in Canada
Abstract
Floods and droughts are traditionally analyzed in isolation; therefore, their disastrous compounding impacts can be underestimated in risk reduction measures. To characterize the corresponding effects of such hydro-hazards, we study the spatial and temporal characteristics of concurrent high and low flows over Canadian watersheds for the historical period of 1963 to 2012 based on the run theory. The frequency, duration, and magnitude of these events are analyzed using 84 Reference Hydrometric Basin Network (RHBN) and 18 World Survey of Canada (WSC) gauges across the Canadian eco-zones. The threshold approach is consistently applied to all gauge records to derive high and low flows representing flood and drought events at the annual and seasonal time scales. The historical changes in the individual and joint behavior of floods and droughts are investigated using the Spearman rank test and Probability Summation (PS) Index. Further, the influences of low-frequency variability modes on the corresponding joint occurrences are assessed. The spatial and temporal characteristics of concurrent droughts and floods are quite diverse across different regions in Canada. The duration of the two extremes shows increasing trends, mostly in southern Quebec and southeastern British Columbia. Western Canada shows a positive correlation between the two extremes over the past 25 years, whereas in the east negative correlations between the two hazards are detected. The results of this study can lead to improvements in future water resource management in Canada.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2021
- Bibcode:
- 2021AGUFM.H45ZA.12R